JPS6069670A - Developing device - Google Patents

Abstract

PURPOSE:To make a device small-sized, and to stabilize an image quality by constituting so that a magnet roller and sleeve are rorated by the first and the second transfer mechanisms through the first gear engaged to a rack of a moving unit of an electrostatic recording paper. CONSTITUTION:For instance, when executing a development of cyan-color, an electromagnet 43 corresponding to a developing unit 25 of cyan-color is operated, and the upper part of a corresponding lever 42 is adsorbed. Therefore, on the way of an advance of a moving unit 16, a straight running cam 22 depresses the lever 42 of the developing unit 25 of cyan-color, turns selectively this developing unit 25, and raises a developing roller 28 to a developing position. At the same time first gear 33 rises and is engaged to a rack. Therefore, a magnet roller 28b is rotated by the first transfer mechanism 31, and on the other hand, since a rotation supporting shaft 35 rotates, a sleeve 28a is rotated by the second transfer mechanism 32, and the development of cyan-color is executed. According to such a constitution, a device is small-sized, and a stable color copying image is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application This invention relates to a developing device used in dry type electrophotographic copying bags.

As a developing method of a conventional electrophotographic copying device, a magnetic brush type developing roller is used to selectively adhere a powdery developer containing a magnetic material to an electrostatic recording medium on which an electrostatic latent image is formed, thereby developing the image. There is a method. An example of a color developing device of this type will be explained with reference to FIG. ), (3a) (3b) (3c) is the transport path (2)
Three developing units are arranged in parallel orthogonally below the developing position of the developer container (5a ) (5b) (5c), and a magnetic brush type developing roller (6a) rotatably mounted with a part of the outer peripheral surface along the axial direction protruding from the upper opening of each developer container (5a) (5b) (5c). (6b) (6c) and
Each developing roller (6a) (6b) (6c) has developer (4
a) It has developer supply rollers (7a) (7b) (7c) that supply (4b) (4c). Developing roller (
6a) has a structure in which a multi-polar magnetic roller (6e) is housed in a cylindrical sleeve (6a) made of a non-magnetic material so as to be rotatable coaxially and in opposite directions.Although not shown, another developing roller (6b) ( 6c) also has the same structure. Then, developer (4a) (4b) is placed on the outer periphery of the sleeve (6d).
A magnetic brush is formed according to (4c). (8a) (8
b) (8c) is each developing roller (6a) (6b) (
6c), and (9) is a selective lifting mechanism that selectively raises each developing unit (3a) (3b) (3c).
10b) (10c) to each container (5a) (5
b) Fix the other leg piece to the side wall of each container, spaced apart from the bottom of (5c), and attach each container (5a) (5b) (5c)
A rotary shaft (12a, 12b, 12e) is fixed to one end below the rotary shaft (
11a ) (11b ) (11c ) disk (12
a) (12b) (12c), the rotating shaft (11a) (1
1b) (11c) Push-up bottles (13a) (13b) (13
c) are protruded, and the push-up bottles (13a) (13b)
(13e) and leaf spring (10a>(10b)(10c)
It was designed to push up the

This rotation axis (11a) (11b > (11c)
rotates periodically, and when one push-up pin (13a) rises toward the center of the corresponding rotating shaft (Ila), the push-up pin (13a) pushes up the leaf spring (10a) and the corresponding developing unit (3a>) is selected and raised.The raised developing unit 1-(3a) is the electrostatic recording paper (1) whose magnetic brush of its developing roller (6a) moves on the conveyance path (2).
During this time, the developing roller (6a
) continues to rotate at an appropriate speed according to the moving speed of the electrostatic recording paper (1) to perform development. After development and fixation, latent images corresponding to different primary colors are formed on the electrostatic recording paper (1), and the above operations are repeated with the development units (3a) (3b) (3).
The development by the selective increase in c) is carried out a total of three times, and a predetermined color copy image is obtained on the electrostatic recording paper (1).

By the way, the developing roller of this device must be rotated at an appropriate speed to match the moving speed of the electrostatic recording medium in order to achieve high-quality development, and a dedicated motor is required for this purpose, making the entire device complicated. There was a problem that it was large and expensive. In addition, it is difficult to always precisely adjust the moving speed of the electrostatic recording medium and the rotational speed of the developing roller, resulting in a problem that the phenomenon tends to become unstable.

C.8 Purpose of the Invention In view of the above-mentioned problems, an object of the present invention is to provide a developing device in which the problems are improved or eliminated.

29 Structure of the Invention The present invention provides a moving unit that supports an electrostatic recording medium and moves along a conveying path with a rank fixed to the lower side surface thereof, and an opening of a bottomed cylindrical developer container that accommodates developer. A developing roller in which a magnetic screw 1 roller is arranged coaxially and independently of each other in a sleeve is rotatably mounted with a part of its outer circumferential surface along the rotation axis protruding from the opening end, and the developing roller is rotatably mounted below the conveyance path. The axis of the developing roller is made substantially perpendicular to the moving direction of the moving unit, and the developing unit is placed close to the trace of movement of the electrostatic recording medium on the outer peripheral surface of the developing roller, and the magnetic screw 1 is freely rotatable on the axis of the roller. a moving unit including a first gear supported and engaged with a rank of the moving unit; and first and second rotation transmission mechanisms for transmitting rotation of the first gear to an axis of the magnetic roller and an axis of the sleeve, respectively; The first gear engaged with the rank is rotated by the movement of the first gear, and the magnet roller and sleeve of the developing roller are further rotated via the first and second rotation transmission mechanisms.

This eliminates the need for a dedicated drive source for the rotation of the developing roller, making the entire device smaller and lower in cost, and ensuring that the moving speed of the electrostatic recording medium and the rotating speed of the developing roller are always kept in a constant relationship. Therefore, stable and high-quality development is always possible.

Embodiment 2 to 5 show specific examples of the color developing device according to the present invention. In the figures, (15) is an electrostatic recording medium such as electrostatic recording paper or a photosensitive plate, Recording paper, (16)
is a moving unit that holds the electrostatic recording paper (15) and moves it back and forth along the conveyance path (17).
The feed screw shaft (18) screwed with the nut (19) is placed along the negative end of the conveyance path (17), and the guide rail (21) is placed parallel to the feed screw shaft (18). A boulder (20) that holds the electrostatic recording paper (15) on the bottom surface is fixed to the guide rail (21).
A linear cam (22) having a substantially trapezoidal side surface shape is vertically fixed on the outer side of the lower surface of the cam 0), and a rack (23) is installed in the axial direction inside the linear cam (22).

is fixed. The electrostatic recording paper (15) supported by the holder (20) reciprocates along the conveyance path (17) by forward and reverse rotation of the feed screw shaft (18).

(24) (24) is a pair of outer walls (25a
) (25b) (25c) are cyan, magenta, and yellow developing units arranged in parallel between both outer walls (24) (24), respectively! J Both have the same structure and are cylindrical developing containers (26a) with bottoms arranged with the opening facing upward.
Cyan, magenta, and yellow developers (27a) (27b) (27c) are stored in (26b) (26c), and the cylindrical sleeve (28) is placed in the opening of the developer container (26).
a) A magnetic brush type developing roller (28) in which magneto 1 rollers (28b') are arranged coaxially and independently rotatable, is rotated with a part of its outer circumferential surface along the axial direction protruding. A developer supply roller (29) that is freely attached and supplies the developer (27) to the developing roller (28).
It is rotatably mounted.

Further, a gear group (31) is attached to one outer surface of each developer container (26) on the naso l-(19) side. This is the rotating shaft of the magnetic roller (28b) of the developing roller (28).
28c), a second gear (34) coaxially fixed to the rotating shaft (28c) outside the first gear (33), and a developer container (26). The first and the second
It is composed of a third gear (36) and a fourth gear (37) that are respectively engaged with the gear. The first gear (33) is located on the movement UL trace of the rank (23) of the Nando (19) when the developing unit (25) is selectively raised.
) and rotates. This first gear (33) has a third gear (36), and the second gear (34) has a fourth gear (1).
= (37>) is always connected, and the rotational force of the first gear (33) is transferred from the third gear (36) to the fourth gear (37) and then to the second gear.
It is transmitted to the gears (34), and each rotates at a relative speed determined by each gear ratio.

(32) is the outer surface of one side opposite to the gear group (31) of the developer container (26), and as shown in FIG.
The first pulley (35) is coaxially fixed to the rotating shaft (28d) of the sleeve (28a) of the developing roller (28).
), a third pulley (40) coaxially fixed to the rotating shaft (29') of the developer supply roller (29), and the first to third pulleys ( 38
) (39) This is a rotation transmission mechanism consisting of a bell I-(41) stretched between (40) and (41). The rotational force of the rotational support shaft (35) is transmitted from the first pulley (38) to the second and third pulleys (39) and (40) via the belt (41), the sleeve (28a) and the developer supply roller ( 29) rotates.

2nd gear (34), 3rd gear (36), 4th gear (3
7), the rotation of the first gear (33) is controlled by the magnet roller (2).
8b), the third gear (36), the rotation support shaft (35), and the first pulley (38).
, second pulley (39), third pulley (40),
The bell l-(41) constitutes a second rotation transmission mechanism that transmits the rotation of the first gear (33) to the sleeve (28a). (30) is a selective lifting mechanism that selectively raises and lowers the developing unit SL- (42) and the Nando (19) fixed to the exceptional surface of the developing container (26) where the gear group (31) is located. It consists of a linear cam (22) fixed to the lever (42), and an electromagnet (43) fixed to the inner surface of the outer wall (24) facing the upper end of the lever (42). Lever (42)
is a dogleg-shaped flat plate made of magnetic metal, the lower part of which is fixed to the -exception surface of the developer container (26), and the upper part of which is fixed to the second and fourth parts.
The gear <34) extends obliquely upward along the outer surface of the gear (37), and a pulley (44) is attached to its tip, and the upper part of the pulley (44) is held so as to be elastically deformable outward in the axial direction of the magneso 1 roller. . Further, in normal operation, the upper end of the lever (42) and the electromagnet (43) face each other with a certain gap g so that the linear cam (22) can pass therethrough, as shown in FIGS. 6 and 7. When the electromagnet (43) is energized, the upper end of the lever (42) moves to the electromagnet (43) as shown in Figures 8 and 9.
The straight cam (22) is magnetically attracted to the lever (43) and positioned at the second position of the movement locus of the straight cam (22), and the straight cam (22) pushes down the pulley (44) on the second line of the lever (42) and passes through.

When the lever (42) is pushed down by the movement of the linear cam (22), the developing unit (25)
) to raise the outer peripheral surface of the developing roller (28) to a fixed position where the magnetic brush comes into contact with the electrostatic recording paper (15) moving on the moving path (17). When the linear cam (22) passes over the lever (42), the developing unisol (25) descends to its original position, and the electromagnet (43)
When the energization is stopped, the lever (42) separates from the electromagnet (43) and returns to its original position. Such selection V<lifting mechanism (
The adoption of 30) eliminates the need for a special power source for raising the developing unit selection, making it possible to make the entire apparatus more compact and cost-effective.

Next above! 1! ;I will explain the developing operation of Ji3. For example, an electrostatic latent image corresponding to a cyan developer is first formed on an electrostatic recording medium, such as an electrostatic recording paper (15), and then moved to a developing device by a moving unit (16). One electromagnet (43) corresponding to the cyan developing unit (25) is activated to attract the upper part of the corresponding leno<- (42). Then, while the moving unit (16) is moving forward, the linear cam (22)
) is the lever (42) of the cyan developing unit I-(25).
) and press down ke"'C;-0)T'4 image unit (25)
Selectively rotate the developer 7-ra (28) to raise it to a normal position where it can be developed. At the same time, the first gear (33) rises and engages with the gear (23) (see FIGS. 8 and 9). If this state is maintained and the moving unit (16) continues to move forward, the first gear (3
3) rotates clockwise as shown in Fig. 8, thereby causing the third
, 4th gear (36) (37) counterclockwise, 2nd gear (3
4) rotates clockwise at a relative speed determined by each gear ratio. As a result, the rotational support shaft (35) rotates counterclockwise, the magnetic nozzle roller (28b) rotates clockwise, and on the other hand, the rotational support shaft (35) rotates counterclockwise, so the 11th (38) rotates counterclockwise, and the , the 31st pulley (39) <40) rotates counterclockwise so that the sleeve (28a) is connected to the first and second pulleys.
It rotates counterclockwise at a speed determined by the outer diameter ratio of (38) and (39), and the electrostatic recording paper (15) is sequentially developed with a cyan developer. Development is done in this way, and the moving unit I
- (16) passes the developing position and development is completed, the linear cam (22) separates from the lever (42), the developing unit (25) lowers, and the operation of the electromagnet (43) is stopped, returning to the original state. to be restored. From now on, the mobile unit (16
), the linear cam (22) is sent through the gap g to the fixing position in front, performs the fixing process on the electrostatic recording IE (15), moves backward on the movement path (17), and transfers it onto the electrostatic recording paper (15). The next electrostatic latent image is formed and the above operations are repeated to repeat development and fixing to obtain a color copy image.

Note that the present invention is not limited to the above-mentioned embodiments, and for example, the rotation transmission mechanism (32) may use not only gears and belts but also friction to transmit rotation.

The electrostatic recording medium may also be a photosensitive plate, which is also applicable to the PPC electrophotographic method in which an electrostatic charge is applied to the photosensitive plate by corona charging and then exposed to light to create an electrostatic latent image, which is then transferred to plain paper after development. can.

3. Effects of the Invention As explained above, according to the effects of the present invention, the power source dedicated to rotating the developing roller can be omitted, making it easier to simplify the structure, downsize, and reduce the cost of the entire apparatus. Furthermore, since the relative relationship between the rotational speed of the developing roller and the moving speed of the electrostatic recording paper is maintained at one point, stable and high-quality development is always possible even when the developing speed is changed.

[Brief explanation of the drawing]

Figure 1 is a partially sectional side view showing an example of a developing device;
FIG. 3 shows a portion IWii7 showing an embodiment of the present invention.
ii Side view and opposite side view, Figures 4 and 5.
A-/', a sectional view taken along lines A-/' and B-B in the figure, FIGS. 6 and 7 are a side view of a part of FIG. 2 during one operation, and C-C.
FIGS. 8-1 and 9 are side views of a portion of FIG. 2 when a portion is selectively raised, and a partially enlarged sectional view taken along line D--D. (15) - electrostatic recording medium, (1B) - mobile unit,
(17) - service route, (23) - rank, (25
) -Developing unit, (26)・-Developing container, (27)
- Developer, (2B) - Developing roller, (28a) - Sleeve, (28b) - Magnet roller, (33) - First gear, (34) (36) (37) - First rotation transmission mechanism , (35) (36) (38) (39
) (40)-Second rotation transmission mechanism. Agent Gangwon Province h1～1

Claims (1)

[Scope of Claims] fll A movable unit 7 that supports an electrostatic recording medium and moves along a conveyance path with a rank fixed to its lower side surface, and a bottomed cylindrical developing container that stores developer. A developing roller, in which magnetic rollers are coaxially arranged independently and rotatably in a sleeve, is rotatably installed in the opening with a part of the outer circumferential surface along the axis of rotation protruding from the opening end, and a developing roller is rotatably mounted below the conveyance path. A developing unit in which the axis of the developing roller is substantially perpendicular to the moving direction of the moving unit and the outer circumferential surface of the developing roller is placed close to the moving trajectory of the electrostatic recording medium, and a moving unit supported on the axis of a magnetic roller so as to be freely rotatable. a first gear that engages with the rack; and first and second gears that transmit the rotation of the first gear to the shaft of the magnet roller and the shaft of the sleeve, respectively.
a rotation transmission mechanism, the movement of the moving unit rotates the first gear engaged with the rank, and further rotates the magnetic roller and sleeve of the developing roller via the first and second rotation transmission mechanisms. A developing device characterized by: (2) A patent characterized in that a plurality of developing units are selectively arranged so as to be freely movable up and down along a conveyance path, and the rack of the moving unit is engaged with the first gear of the selected developing unit. A developing device according to claim 1.